Spark-plug tester



'v l m M 1 t u m m a and o. L. BURcH SPARK PLUG TESTER Filed May22, 192

Patented May 1925.

Psfrilvr` oFFlcE.

' onA L. BUncH, or Lir'rLn'roN, ooLonADo.

SPARK-PLUG TESTER.

Application filed May 22,

To all 'whom it may oon-cera.'

Be it known that I, OIL-i L. BURCH, citi- Zen of thev United States, residing `at Littleton, in the county of Arapahoe and State of Colorado-,have invented certain new and useful Improvements in Spark-Plug Testers, of which the following is a specification. ,This invention relates lto an improved 4spark plugtester andseeks, as one of its principal'objects, to provide a deviceof this character4 which kmay be employed in con- `junction with `the .primary and secondary posts of one of the induction coils of a Ford vehicle for testing the plugs of thefvehicle engine.

invention seeks, as a further object,

` f l to provide La device which may vbe perma` y 3nently mounted upon the coil posts of one of the coils .without interfering with the functioning `of the ignition system of the. vehicle y'but which willrutilize the coil in testing ,a plug, whenever it is ldesired to make atest. W

And the invention seeks, as a still further object, to yprovide ya device which may be .readily applied and which will be of simple construction so vthat the devicey may be produced and` sold at moderatecost.

, Other kand incident-al objectswill appear hereinafter.

In the drawings: f l

` Figure 1 is axperspective viewof my im-` proved yspark plug tester.

y Figure 2 is an enlarged vertical sectional view showing the kdevice mounted upon the primaryand secondarypostsof one of the coils of a Ford vehicle, and f Figure 3 is; a diagrammatic view showing a portion of the ignition system of the vef hicle and illustrating the` manner in lwhich the device is interposed yin said system. f

In carrying thel invention into effect, I employ anoblong kbody plate or member 10 which is formed of a stripv of suitable insulating material and mounted upon said plate at the lower end thereof is anangle bracket 11 riveted or otherwise secured to the plate. Formed through the plate and through said bracket is an opening y12 and formed `in the bracket. near the free end thereof is asimilar opening 13. Mounted upon the plate 1() near its upperend is a spring clip 14 which mav` like the bracket 11, be rivetedor otherwise secured to said plate. This clip is provided with companion arcuate spring lingers 15 preferably'formed 1923. Serial No. 640,748.

at their outer ends with laterally directed ylips 16` and rising from the clip is akswitch arm 17 offset to extend in parallel relation to the body plate. Formed through` the In conjunction with the switch arm I employ a conductor l9 which may be formed of a low resistance insulated wire and soldered or otherwise secured to said wire at one end thereof is a terminal 2O secured tothe upper end of the body plate 10 by a rivet or other suitable fastening device 21 forming a con# tact post inthe rear of the switch arm.

- In 4order to clearly bring out the manner of use of my improved spark plug tester, I have, in Figures2 and 3 of the drawings, shown the device applied. As previously intimated, the device is especially designed for use in connection with Ford vehicles and in Figure 2 I have conventionally shown the dash of such a vehicle at 22. The usual coil box ofthe vehicle is indicated at 23 and projecting from the coil bo'X forwardly through the dash are the usual coil posts, the ,posts .of the first coil, or the coil :at the right, being indicated at 24y and 25 respecv tively, vIn mounting the improved device, the nuts upon these posts are removed when the forward ends of the posts `are inserted through the openings 12 and 18 of the device. `The body plate 10 n will thus abut the, usual porcelains upon the posts so that whenfsaid nuts are again applied, the device'` ywill be rigidly mounted upon said posts to extend Y vertically therebetween. In replacing the nuts the usual primary and secondary' circuit'v wires 26 and 27 of the kvcoil are connected with the postsby said nuts.

Thus, under ordinary conditions, Lthe coil chronism After the body plate has been arranged in position the conductor 19 is eX- tended across to the usual center radiator brace rod 28 of the vehicle and wrapped abouty said rod for electrically grounding the conductor.

p In Figure 2, I have shown a conventional plug 29 in position upon the device so as to be tested. As illustrated, the plug is inverted, when the center electrode of the plug is inserted through the opening- 13 in the bracket 1l while the base end of the plug is engaged between the spring fingers l5 of the clip 14. The usual switch of the ignition system of the vehicle is then turned to close the primary circuit of said system from the-battery of the vehicle through the coils. Accordingly, by then flexing the switch arm 17 to engage the contact 21, the primary circuit of the first coil will be closed through the ground conductor 19 while the secondary circuit oft said coil will be closed through the center electrode oi' the plug, the clip 14:, the switch arm li', contact 21, and conductor 19 to ground. Thus7 if the plug is in good condition, a steady hot spark will be caused to jump from the center electrode of the plug` across to the coacting electrode upon the plug' shell. On the other hand, if the plug is dcfective, either no spark at all or, at least, a very weak spark will occur between the electrodes of the plug', thus indicating the faulty condition of the plug. I accordingly provide a device whereby each of the plugs of an engine may be efli'ciently tested while the presence of the device upon the vehicle will in no Way hamper the normal operation of the ignition system of the Vehicle.

Having thus described the invention, what is claimed as new is:

1. rI`he combination with an induction coil, angl primary and secondary circuit posts associated therewith, of Contact means electrically connected permanently with one of said posts, contact means electrically connected permanently with the other of said posts to engage the shell of a spark plugr having one of the coacting electrodes thereof in contact with said first mentioned means` and a switch exposed to be manual y flexed for electrically grounding the primary circuit and closing the secondary circuit of the coil through the electrodes of the plug.

2. In a vehicle engine ignition system, the combination of an induction coil, primary and secondary circuit posts associated therewith, means mounted upon said posts and electrically connected permanently therewith to accommodate a spark plug having one of the coacting electrodes thereof in circuit with the secondary post, and a switch exposed to be manually flexed for electrically grounding the primary circuit of the cil as well as closing the secondary circuit of said coil through the electrodes of the plug.

3. A spark plug tester including companion contactrelements for permanent mechanical and electrical connection to the primary and secondary circuit posts of an induction coil to receive a spark plug having one of the coacting electrodes thereof in circuit with the secondary post, and a switch exposed to be manually flexed for closing a circuit through the primary post as well as closing a circuit through the secondary post and through the electrodes of the plug.

A spark plug tester including a body member, spaced contact elements carried thereby for permanent mechanical and electrical connection to the primary and secondary posts of an induction coil and formed to receive a spark plug` in circuit with said elements, and a switch exposed to be manually flexed for electrically grounding one ot said elements.

5. A spark plug tester including a strip of insulating material apertured near its ends to receive the primary and secondary posts of an induction coil therethrough, a bracket near one end of the strip apertured to receive one of said posts, and a spring clip near the opposite end ot the strip to engage the shell of a spark plug resting on said bracket and having the center electrode thereof engaged with the bracket, said clip beine' 'formed with an upstanding resilient switch arm apertured to receive the other of said posts and adapted to be manually fiexed for closing` a circuit through the plug.

In testimony whereof I affix my signature. f

ORA L. BURCH. [ns] 

